WARNING: Using the `raise_error` matcher without providing a specific error or
message risks false positives, since `raise_error` will match when
Ruby raises a `NoMethodError`, `NameError` or `ArgumentError`,
potentially allowing the expectation to pass without even executing
the method you are intending to call.

To be quite honest, I’ve never really thought about that but it’s obvious that this advice is wise.
So wise that when searching for code not specifying an error and adding one, I’ve stumbled upon that kind of error: